Organopolysiloxanes containing carboxyl groups are employed, for example, as textile finishing agents. Good soft handle effects coupled with a low tendency to yellow are achieved with the textiles treated with these compounds. Organopolysiloxanes containing carboxyl groups are also employed for finishing leather and as release agents.
The preparation of organosilicon compounds containing carboxyl groups by reaction of .alpha.-olefins which have a carboxyl group provided with a silyl protective group with silanes or siloxanes which have an Si-H group and subsequent hydrolysis of the silyl protective groups is described in EP-A-196 169. However, this process is very involved, since the hydrolysis of the silyl ester requires large amounts of water and long reaction times at high temperatures because of the heterogeneous system. The water employed in excess must then be removed from the heterogeneous system. This is achieved by distillation with the aid of an entraining agent, such as toluene, used to reduce foaming during the distillation.